Phineas and Ferb: Across the 2nd Dimension is a game based on the original Disney Channel movie that was inspired by the hit cartoon. The titular characters find themselves trapped in an alternate dimension after following the evil Dr. Doofenshmirtz through a portal created by a machine he calls an "Otherdimensionator." There they find an even more evil version of Dr. D. and band together to make their escape. That's where the game picks up.

Players will be able to control Phineas, Ferb, Agents P and T (Agent T was created specifically for this game), and Phineas and Ferb doppelgängers from the alternate dimension. 2nd Dimension is part old-school co-op shooter, and part platformer almost in the vein of the arcade version of Teenage Mutant Ninja Turtles. It utilizes a very similar formula: go to an area, defeat "x" number of bad guys, pick up a few puzzle pieces in the name of progress, move on to the next area, rinse and repeat. Fans of the show will recognize the references to blueprints and mini "collect-a-part" missions scattered throughout the levels. You'll also occasionally come across levels that play like slightly more light-hearted versions of Space Harrier, jetpack and all.

Each character has his or her own passive ability. Phineas has regenerative health, Ferb can take more damage, and so on. In addition, when playing in the Space Harrier-esque levels, players can work together to perform special attacks. It should be noted that there are always two characters on screen regardless of whether or not two people are actually playing. In some games this type of gameplay proves to be irritating, but in this instance the A.I. does a fairly good job of handling itself. I can't remember a time when it got in the way at all. A player can also choose to switch back and forth between the two characters and, for the most part, I found that the transition was smooth.

Progressing through the levels was rarely a hard task, since the difficulty was designed for the younger age group that makes up the majority of the fan base. This isn't a bad thing unto itself. I did, however, struggle to keep myself engaged during some of the later levels, where it seems the designers had either run short on fresh ideas or were running out of time. This wasn't a problem throughout, though. Earlier areas, like the Balloon Dimension or the Old-Timey Dimension, were fun and imaginative, but I fought to stay interested later on.

It's the same story with enemy variety. While early levels featured some interesting foes (SPOILER: you get to eat one of the bosses), the enemies from later levels hardly required much more than mashing the fire button. Again, this could be due to the fact that the game is catered toward younger players.

One interesting aspect of the gameplay is that all of the weapons are upgradable. Each of them also has slots for special boosters, some cosmetic and others practical. It seems a lot of attention was paid to making sure players were never bored with their options. Truthfully, however, I mostly stuck with the first weapon, the baseball launcher. I found it frustrating at times that there was no way to adjust the camera, though this fixed camera isn't always a bad thing.